Global Electroweak Fit Constraints on the Two-Higgs-Doublet Model in Light of the CDF W -Boson Mass

Abstract

The recent measurement of the $W$ boson mass by the CDF II collaboration exhibits a significant tension with the Standard Model (SM) prediction and other experimental determinations. In this work, we investigate the implications of this result within the framework of the Two-Higgs-Doublet Model (2HDM), focusing on radiative corrections to electroweak precision observables parameterized in terms of the oblique parameters $\Delta S$, $\Delta T$, and $\Delta U$. Using global electroweak fits, we analyze how the inclusion of the CDF measurement modifies the preferred parameter space. We show that the observed shift in $m_W$ can be accommodated in the 2HDM through enhanced contributions to $\Delta T$, arising from mass splittings in the scalar sector. The resulting constraints on the scalar spectrum are presented and compared with those obtained using previous electroweak data. These results highlight the role of precision observables in probing extended Higgs sectors and provide updated bounds on viable 2HDM parameter space.

Comments: 22 pages, 22 figures. We analyze electroweak precision observables in the Two-Higgs-Doublet Model (2HDM), with emphasis on oblique parameters and the impact of the CDF W-boson mass measurement. The results highlight the role of scalar mass splittings in shaping the allowed parameter space. Minor updates and improvements may appear in subsequent versions